gh-102247: http: support rfc9110 status codes (GH-117611)

rfc9110 obsoletes the earlier rfc 7231. This document also includes some
status codes that were previously only used for WebDAV and assigns more
generic names to these status codes.

ref: https://www.rfc-editor.org/rfc/rfc9110.html#name-changes-from-rfc-7231

- http.HTTPStatus.CONTENT_TOO_LARGE (413, previously
  REQUEST_ENTITY_TOO_LARGE)
- http.HTTPStatus.URI_TOO_LONG (414, previously REQUEST_URI_TOO_LONG)
- http.HTTPStatus.RANGE_NOT_SATISFYABLE (416, previously
  REQUEST_RANGE_NOT_SATISFYABLE)
- http.HTTPStatus.UNPROCESSABLE_CONTENT (422, previously
  UNPROCESSABLE_ENTITY)

The new constants are added to http.HTTPStatus and the old constant names are
preserved for backwards compatibility.

References in documentation to the obsoleted rfc 7231 are updated

Lib/test/test_httpservers.py

@@ -1205,7 +1205,7 @@ class BaseHTTPRequestHandlerTestCase(unittest.TestCase):
         # Issue #10714: huge request lines are discarded, to avoid Denial
         # of Service attacks.
         result = self.send_typical_request(b'GET ' + b'x' * 65537)
-        self.assertEqual(result[0], b'HTTP/1.1 414 Request-URI Too Long\r\n')
+        self.assertEqual(result[0], b'HTTP/1.1 414 URI Too Long\r\n')
         self.assertFalse(self.handler.get_called)
         self.assertIsInstance(self.handler.requestline, str)